Henneberg M, Louw G J
Department of Anatomy and Human Biology, Medical School, University of the Witwatersrand, Parktown, S. Africa.
Am J Phys Anthropol. 1993 Jun;91(2):235-44. doi: 10.1002/ajpa.1330910209.
A previous study (Henneberg and Louw: Am. J. Hum. Biol. 2:227-233, 1990) showed that urban schoolchildren born between August and January were taller and heavier by 13 to 17% of the standard deviation (S) than those born in February to July. The study is now extended to 1,522 impoverished rural schoolchildren from the Little Karoo district of S. Africa and to 804 German Shepherd dogs kennelled at a breeding station in the Transvaal. The dogs provided a quasi-experimental model because for all of them nutrition and living conditions were practically identical throughout the year. The month-of-birth effect in the body weight of dogs was found to be stronger than that in urban children: dogs born between August and January were heavier by 22% of S than those born in February through July. In rural children the effect is present, but its magnitude is somewhat less and the peak is shifted by 2-3 months. Children born in May through October are 11% of S lighter than those born in November through April. It seems that living conditions characteristic of extreme poverty tend to diminish the effect. In both the animal model and rural children the month-of-birth effect decreases with advancing age and is more pronounced in males than in females. These findings are in agreement with previous observations in urban children from Cape Town. Since the living conditions of dogs and humans differ, as do the climatic conditions of Cape Town, Little Karoo and the Transvaal, it is surmised that the similarity of the effect may result from factors influencing the entire planet in a uniform way.
此前一项研究（亨内贝格和洛：《美国人类生物学杂志》2:227 - 233，1990年）表明，8月至次年1月出生的城市学童比2月至7月出生的学童身高更高、体重更重，超出标准差（S）的13%至17%。该研究现扩展至南非小卡鲁地区的1522名贫困农村学童以及德兰士瓦一个繁育站饲养的804只德国牧羊犬。这些狗提供了一个准实验模型，因为它们全年的营养和生活条件实际上都相同。研究发现，狗体重的出生月份效应比城市儿童的更强：8月至次年1月出生的狗比2月至7月出生的狗体重超出标准差的22%。农村儿童中也存在这种效应，但其程度稍小，峰值偏移了2 - 3个月。5月至10月出生的儿童比11月至次年4月出生的儿童体重轻标准差的11%。极端贫困的生活条件似乎会减弱这种效应。在动物模型和农村儿童中，出生月份效应都随着年龄增长而减小，且在男性中比在女性中更明显。这些发现与之前对开普敦城市儿童的观察结果一致。由于狗和人类的生活条件不同，开普敦、小卡鲁和德兰士瓦的气候条件也不同，据推测，这种效应的相似性可能是由以统一方式影响整个地球的因素导致的。
